In this paper, Ti-6Al-4V/TiAl3 laminated composites were butt welded by tungsten argon arc welding (TIG). The effects of different welding parameters on the microstructure and mechanical properties of the joint were investigated. The hot rolled Ti-6Al-4V /TiAl3 laminated composites can be reliably connected by TIG welding to avoid the phenomenon of joint embrittlement. The intermetallic compound at the bottom of the plate melts under the influence of heat radiation in the welding process, and the reaction between liquid TiAl3 and Ti generates Ti3Al, TiAl and so on, which causes the depletion zone of Ti atoms around the intermetallic compound and accelerates the diffusion migration of Ti atoms, resulting in the joint profile divided into two parts: The upper part is the weld zone of melting and solidification, and the bottom is the diffusion connection caused by thermal radiation. The overall joint has no obvious defects, and the weld zone is a network of α phase and acicular martensite. The tensile strength of the welded joint is 343MPa, about 90% of the base metal, and the fracture is ductile brittle mixed fracture.